Roofs and flat roofs
A higher gutter discharges straight onto a lower roof slope instead of into a downpipe. What can that water do that a clear gutter on the main eaves will not show?
The higher gutter that discharges onto the lower roof is throwing water where a clear gutter at the main eaves will not show it. Instead of entering a downpipe, that water lands on the lower covering and the details under it. A tidy eaves gutter can still leave this slope taking a concentrated flow. The survey can see the discharge. It has not measured the flow, and it has not proved that the lower roof is already leaking.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
A roof slope is asked to shed the rain that falls on it, not to swallow a gutter-full from the roof above. Discharge onto the slope can work under a flashing or soak an edge in a way the main eaves never reveal. The finding is the path the water takes. It is not a rating of every slope, and it is not a repair price.
Photograph the outlet and the patch of lower roof it hits. Ask whether the covering, the upstand or the ceiling beneath showed a stain. Reconnecting that gutter into a downpipe is the practical next question. Until that is done, a clear gutter on the main eaves is not the whole of the rainwater picture for this particular house.
What should you ask your surveyor?
- Where does the higher gutter let go, and which part of the lower slope does it hit?
- Did you see a tired flashing or a stained ceiling under that point of discharge?
- Are you separating this outlet from the condition of the main eaves gutter?
What are the typical next steps?
- Stop the higher gutter discharging onto the lower roof slope.
- Do not treat a clear main eaves gutter as the whole rainwater picture.
- Check the lower covering and the room below before you assume no water entered.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
If the main gutter is clear, can this discharge be set aside?
No. The main eaves are a different run. Water thrown onto the lower slope is not shown by a clear gutter somewhere else on the house.
Has the survey proved that the lower roof already leaks?
No. It has recorded where the higher gutter throws its water. A leak is a further observation, not something this path proves by itself.